0~31及127(共33个)是控制字符或通信专用字符(其余为可显示字符),如控制符:LF(换行)、CR(回车)、FF(换页)、DEL(删除)、BS(退格)、BEL(振铃)等;通信专用字符:SOH(文头)、EOT(文尾)、ACK(确认)等;ASCII值为 8、9、10 和 13 分别转换为退格、制表、换行和回车字符。它们并没有特定的图形显示,但会依不同的应用程序,而对文本显示有不同的影响。
32~126(共95个)是字符(32sp是空格),其中48~57为0到9十个阿拉伯数字;
65~90为26个大写英文字母,97~122号为26个小写英文字母,其余为一些标点符号、运算符号等。
常见ASCII码的大小规则
0~91)数字比字母要小。如 “7”<“F”;
2)数字0比数字9要小,并按0到9顺序递增。如 “3”<“8” ;
3)字母A比字母Z要小,并按A到Z顺序递增。如“A”<“Z” ;
4)同个字母的大写字母比小写字母要小32。如“A”<“a” 。
记住几个常见字母的ASCII码大小:
换行LF为0x0A;回车CR为0x0D;空格为0x20;“0”为0x30; “A”为0x41;“a”为0x61。
标准ASCII表
| Bin | Dec | Hex | 缩写/字符 | 解释 |
| 00000000 | 0 | 00 | NUL(null) | 空字符 |
| 00000001 | 1 | 01 | SOH(start of headling) | 标题开始 |
| 00000010 | 2 | 02 | STX (start of text) | 正文开始 |
| 00000011 | 3 | 03 | ETX (end of text) | 正文结束 |
| 00000100 | 4 | 04 | EOT (end of transmission) | 传输结束 |
| 00000101 | 5 | 05 | ENQ (enquiry) | 请求 |
| 00000110 | 6 | 06 | ACK (acknowledge) | 收到通知 |
| 00000111 | 7 | 07 | BEL (bell) | 响铃 |
| 00001000 | 8 | 08 | BS (backspace) | 退格 |
| 00001001 | 9 | 09 | HT (horizontal tab) | 水平制表符 |
| 00001010 | 10 | 0A | LF (NL line feed, new line) | 换行键 |
| 00001011 | 11 | 0B | VT (vertical tab) | 垂直制表符 |
| 00001100 | 12 | 0C | FF (NP form feed, new page) | 换页键 |
| 00001101 | 13 | 0D | CR (carriage return) | 回车键 |
| 00001110 | 14 | 0E | SO (shift out) | 不用切换 |
| 00001111 | 15 | 0F | SI (shift in) | 启用切换 |
| 00010000 | 16 | 10 | DLE (data link escape) | 数据链路转义 |
| 00010001 | 17 | 11 | DC1 (device control 1) | 设备控制1 |
| 00010010 | 18 | 12 | DC2 (device control 2) | 设备控制2 |
| 00010011 | 19 | 13 | DC3 (device control 3) | 设备控制3 |
| 00010100 | 20 | 14 | DC4 (device control 4) | 设备控制4 |
| 00010101 | 21 | 15 | NAK (negative acknowledge) | 拒绝接收 |
| 00010110 | 22 | 16 | SYN (synchronous idle) | 同步空闲 |
| 00010111 | 23 | 17 | ETB (end of trans. block) | 传输块结束 |
| 00011000 | 24 | 18 | CAN (cancel) | 取消 |
| 00011001 | 25 | 19 | EM (end of medium) | 介质中断 |
| 00011010 | 26 | 1A | SUB (substitute) | 替补 |
| 00011011 | 27 | 1B | ESC (escape) | 溢出 |
| 00011100 | 28 | 1C | FS (file separator) | 文件分割符 |
| 00011101 | 29 | 1D | GS (group separator) | 分组符 |
| 00011110 | 30 | 1E | RS (record separator) | 记录分离符 |
| 00011111 | 31 | 1F | US (unit separator) | 单元分隔符 |
| 00100000 | 32 | 20 | (space) | 空格 |
| 00100001 | 33 | 21 | ! | |
| 00100010 | 34 | 22 | " | |
| 00100011 | 35 | 23 | # | |
| 00100100 | 36 | 24 | $ | |
| 00100101 | 37 | 25 | % | |
| 00100110 | 38 | 26 | & | |
| 00100111 | 39 | 27 | ' | |
| 00101000 | 40 | 28 | ( | |
| 00101001 | 41 | 29 | ) | |
| 00101010 | 42 | 2A | * | |
| 00101011 | 43 | 2B | + | |
| 00101100 | 44 | 2C | , | |
| 00101101 | 45 | 2D | - | |
| 00101110 | 46 | 2E | . | |
| 00101111 | 47 | 2F | / | |
| 00110000 | 48 | 30 | 0 | |
续表
| 00110001 | 49 | 31 | 1 | |
| 00110010 | 50 | 32 | 2 | |
| 00110011 | 51 | 33 | 3 | |
| 00110100 | 52 | 34 | 4 | |
| 00110101 | 53 | 35 | 5 | |
| 00110110 | 54 | 36 | 6 | |
| 00110111 | 55 | 37 | 7 | |
| 00111000 | 56 | 38 | 8 | |
| 00111001 | 57 | 39 | 9 | |
| 00111010 | 58 | 3A | : | |
| 00111011 | 59 | 3B | ; | |
| 00111100 | 60 | 3C | < | |
| 00111101 | 61 | 3D | = | |
| 00111110 | 62 | 3E | > | |
| 00111111 | 63 | 3F | ? | |
| 01000000 | 64 | 40 | @ | |
| 01000001 | 65 | 41 | A | |
| 01000010 | 66 | 42 | B | |
| 01000011 | 67 | 43 | C | |
| 01000100 | 68 | 44 | D | |
| 01000101 | 69 | 45 | E | |
| 01000110 | 70 | 46 | F | |
| 01000111 | 71 | 47 | G | |
| 01001000 | 72 | 48 | H | |
| 01001001 | 73 | 49 | I | |
| 01001010 | 74 | 4A | J | |
| 01001011 | 75 | 4B | K | |
| 01001100 | 76 | 4C | L | |
| 01001101 | 77 | 4D | M | |
| 01001110 | 78 | 4E | N | |
| 01001111 | 79 | 4F | O | |
| 01010000 | 80 | 50 | P | |
| 01010001 | 81 | 51 | Q | |
| 01010010 | 82 | 52 | R | |
| 01010011 | 83 | 53 | S | |
| 01010100 | 84 | 54 | T | |
| 01010101 | 85 | 55 | U | |
| 01010110 | 86 | 56 | V | |
| 01010111 | 87 | 57 | W | |
| 01011000 | 88 | 58 | X | |
| 01011001 | 89 | 59 | Y | |
| 01011010 | 90 | 5A | Z | |
| 01011011 | 91 | 5B | [ | |
| 01011100 | 92 | 5C | \ | |
| 01011101 | 93 | 5D | ] | |
| 01011110 | 94 | 5E | ^ | |
| 01011111 | 95 | 5F | _ | |
| 01100000 | 96 | 60 | ` | |
| 01100001 | 97 | 61 | a | |
| 01100010 | 98 | 62 | b | |
续表
| 01100011 | 99 | 63 | c | |
| 01100100 | 100 | 64 | d | |
| 01100101 | 101 | 65 | e | |
| 01100110 | 102 | 66 | f | |
| 01100111 | 103 | 67 | g | |
| 01101000 | 104 | 68 | h | |
| 01101001 | 105 | 69 | i | |
| 01101010 | 106 | 6A | j | |
| 01101011 | 107 | 6B | k | |
| 01101100 | 108 | 6C | l | |
| 01101101 | 109 | 6D | m | |
| 01101110 | 110 | 6E | n | |
| 01101111 | 111 | 6F | o | |
| 01110000 | 112 | 70 | p | |
| 01110001 | 113 | 71 | q | |
| 01110010 | 114 | 72 | r | |
| 01110011 | 115 | 73 | s | |
| 01110100 | 116 | 74 | t | |
| 01110101 | 117 | 75 | u | |
| 01110110 | 118 | 76 | v | |
| 01110111 | 119 | 77 | w | |
| 01111000 | 120 | 78 | x | |
| 01111001 | 121 | 79 | y | |
| 01111010 | 122 | 7A | z | |
| 01111011 | 123 | 7B | { | |
| 01111100 | 124 | 7C | | | |
| 01111101 | 125 | 7D | } | |
| 01111110 | 126 | 7E | ~ | |
| 01111111 | 127 | 7F | DEL (delete) | 删除 |
| 八进制 | 十六进制 | 十进制 | 字符 | 八进制 | 十六进制 | 十进制 | 字符 |
| 0 | 0 | 0 | nul | 100 | 40 | 64 | @ |
| 1 | 1 | 1 | soh | 101 | 41 | 65 | A |
| 2 | 2 | 2 | stx | 102 | 42 | 66 | B |
| 3 | 3 | 3 | etx | 103 | 43 | 67 | C |
| 4 | 4 | 4 | eot | 104 | 44 | 68 | D |
| 5 | 5 | 5 | enq | 105 | 45 | 69 | E |
| 6 | 6 | 6 | ack | 106 | 46 | 70 | F |
| 7 | 7 | 7 | bel | 107 | 47 | 71 | G |
| 10 | 8 | 8 | bs | 110 | 48 | 72 | H |
| 11 | 9 | 9 | ht | 111 | 49 | 73 | I |
| 12 | 0a | 10 | nl | 112 | 4a | 74 | J |
| 13 | 0b | 11 | vt | 113 | 4b | 75 | K |
| 14 | 0c | 12 | ff | 114 | 4c | 76 | L |
| 15 | 0d | 13 | er | 115 | 4d | 77 | M |
| 16 | 0e | 14 | so | 116 | 4e | 78 | N |
| 17 | 0f | 15 | si | 117 | 4f | 79 | O |
| 20 | 10 | 16 | dle | 120 | 50 | 80 | P |
| 21 | 11 | 17 | dc1 | 121 | 51 | 81 | Q |
| 22 | 12 | 18 | dc2 | 122 | 52 | 82 | R |
| 23 | 13 | 19 | dc3 | 123 | 53 | 83 | S |
| 24 | 14 | 20 | dc4 | 124 | 54 | 84 | T |
| 25 | 15 | 21 | nak | 125 | 55 | 85 | U |
| 26 | 16 | 22 | syn | 126 | 56 | 86 | V |
| 27 | 17 | 23 | etb | 127 | 57 | 87 | W |
| 30 | 18 | 24 | can | 130 | 58 | 88 | X |
| 31 | 19 | 25 | em | 131 | 59 | 89 | Y |
| 32 | 1a | 26 | sub | 132 | 5a | 90 | Z |
| 33 | 1b | 27 | esc | 133 | 5b | 91 | [ |
| 34 | 1c | 28 | fs | 134 | 5c | 92 | \ |
| 35 | 1d | 29 | gs | 135 | 5d | 93 | ] |
| 36 | 1e | 30 | re | 136 | 5e | 94 | ^ |
| 37 | 1f | 31 | us | 137 | 5f | 95 | _ |
| 40 | 20 | 32 | sp | 140 | 60 | 96 | ' |
| 41 | 21 | 33 | ! | 141 | 61 | 97 | a |
| 42 | 22 | 34 | " | 142 | 62 | 98 | b |
| 43 | 23 | 35 | # | 143 | 63 | 99 | c |
| 44 | 24 | 36 | $ | 144 | 64 | 100 | d |
| 45 | 25 | 37 | % | 145 | 65 | 101 | e |
| 46 | 26 | 38 | & | 146 | 66 | 102 | f |
| 47 | 27 | 39 | ` | 147 | 67 | 103 | g |
| 50 | 28 | 40 | ( | 150 | 68 | 104 | h |
| 51 | 29 | 41 | ) | 151 | 69 | 105 | i |
| 52 | 2a | 42 | * | 152 | 6a | 106 | j |
| 53 | 2b | 43 | + | 153 | 6b | 107 | k |
| 54 | 2c | 44 | , | 154 | 6c | 108 | l |
| 55 | 2d | 45 | - | 155 | 6d | 109 | m |
| 56 | 2e | 46 | . | 156 | 6e | 110 | n |
| 57 | 2f | 47 | / | 157 | 6f | 111 | o |
| 60 | 30 | 48 | 0 | 160 | 70 | 112 | p |
| 61 | 31 | 49 | 1 | 161 | 71 | 113 | q |
| 62 | 32 | 50 | 2 | 162 | 72 | 114 | r |
| 63 | 33 | 51 | 3 | 163 | 73 | 115 | s |
| 64 | 34 | 52 | 4 | 164 | 74 | 116 | t |
| 65 | 35 | 53 | 5 | 165 | 75 | 117 | u |
| 66 | 36 | 54 | 6 | 166 | 76 | 118 | v |
| 67 | 37 | 55 | 7 | 167 | 77 | 119 | w |
| 70 | 38 | 56 | 8 | 170 | 78 | 120 | x |
| 71 | 39 | 57 | 9 | 171 | 79 | 121 | y |
| 72 | 3a | 58 | : | 172 | 7a | 122 | z |
| 73 | 3b | 59 | ; | 173 | 7b | 123 | { |
| 74 | 3c | 60 | < | 174 | 7c | 124 | | |
| 75 | 3d | 61 | = | 175 | 7d | 125 | } |
| 76 | 3e | 62 | > | 176 | 7e | 126 | ~ |
| 77 | 3f | 63 | ? | 177 | 7f | 127 | del |